20.500.12556/DKUM-66507 The LexA regulated genes of the Clostridium difficile Background: The SOS response including two main proteins LexA and RecA, maintains the integrity of bacterial genomes after DNA damage due to metabolic or environmental assaults. Additionally, derepression of LexA-regulated genes can result in mutations, genetic exchange and expression of virulence factors. Here we describe the first comprehensive description of the in silico LexA regulon in Clostridium difficile, an important human pathogen. Results: We grouped thirty C. difficile strains from different ribotypes and toxinotypes into three clusters according to lexA gene/protein variability. We applied in silico analysis coupled to surface plasmon resonance spectroscopy (SPR) and determined 16 LexA binding sites in C. difficile. Our data indicate that strains within the cluster, as defined by LexA variability, harbour several specific LexA regulon genes. In addition to core SOS genes: lexA, recA, ruvCA and uvrBA, we identified a LexA binding site on the pathogenicity locus (PaLoc) and in the putative promoter region of several genes involved in housekeeping, sporulation and antibiotic resistance. Conclusions: Results presented here suggest that in C. difficile LexA is not merely a regulator of the DNA damage response genes but also controls the expression of dozen genes involved in various other biological functions. Our in vitro results indicate that in C. difficile inactivation of LexA repressor depends on repressor`s dissociation from the operators. We report that the repressor`s dissociation rates from operators differentiate, thus the determined LexA-DNA dissociation constants imply on the timing of SOS gene expression in C. difficile. Clostridium difficile antibiotic resistance toxin regulation SOS system surface plasmon resonance SPR LexA repressor Clostridium difficile rezistenca na antibiotike odpornost na antibiotike regulacija toksinov sistem SOS površinska plazmonska resonanca SPR represor LexA true false true Angleški jezik Slovenski jezik Znanstveno delo 2017-06-29 09:12:47 2017-06-29 09:13:49 2022-07-11 03:07:22 2019-07-11 15:49:49 2014 0 0 str. 1-20 Letn. 14 2014 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1471-2180 577.2 2441492 3097423 10.1186/1471-2180-14-88 1471-2180 URN:SI:UM:DK:WMFMKAWB BMC_Microbiology_2014_Walter_et_al._The_LexA_regulated_genes_of_the_Clostridium_difficile.pdf BMC_Microbiology_2014_Walter_et_al._The_LexA_regulated_genes_of_the_Clostridium_difficile.pdf 1 3D831395DDD4C95165600CBBEEEA3552 1b83f0a06dc7f4dcb6c4d52cc172b51997300fe23dc6e9ec55c92013d8339b4c 51aec8a8-7c0e-11eb-bb7a-00155d0001ca https://dk.um.si/Dokument.php?lang=slv&id=113313 http://bmcmicrobiol.biomedcentral.com/articles/10.1186/1471-2180-14-88 1 https://dk.um.si/Dokument.php?lang=slv&id=113312 Medicinska fakulteta 0 0 0